Multi-cell conduit connection joint

Abstract

A joint, and method for constructing the joint, are provided for connecting sections of multi-cell conduit in an end-to-end manner to produce long runs of conduit for carrying fiber-optic cables or the like, wherein the joints produced will isolate, in a substantially airtight manner, each of the individual cells from the adjoining cells.

I claim: 
     
       1. A multi-cell conduit system having at least two sections of conduit to be joined end-to-end, said system comprising: a first and a second section of multi-cell conduit, each section having an integral web forming a plurality of cells in an interior part of each section, each cell of said first section having an associated cell in said second section defining pairs of associated cells, each of said sections having a main portion and at least one integral connector portion, said connector portions having substantially identical cross-sectional configurations, said connector portions having expanded interior and exterior cross-sectional areas which are greater than interior and exterior cross-areas of said main portions, each of said connector portions extending axially inwardly for a predetermined distance from an end of said conduit section;   each of said pair of associated cells of said first and second conduit sections having an associated cell insert, each of said cells inserts having an external cross-sectional configuration conforming substantially in geometry to an internal cross-sectional configuration of the connector portions of its pair of associated cells; and   a joint between said first and second sections said joint comprising a portion of each of said cell inserts extending into associated cells of the connector portion of the first and the second conduit section, the sections being aligned along their longitudinal axis with the ends holding the inserts facing each other such that a protruding portion of each of the cell inserts enters it associated cell in the opposing conduit section with said sections abutting each other.   
     
     
       2. A system as described in claim 1 wherein the conduit sections are substantially square in external cross-section and contain four cells. 
     
     
       3. A system as described in claim 2 wherein each conduit section has connector portion at both ends of the section. 
     
     
       4. A system as described in claim 2 wherein the conduit sections have rounded corners. 
     
     
       5. A system as described in claim 4 wherein each of the four cells of each conduit section is substantially square in cross-section, each cell having an associated rounded corner. 
     
     
       6. A system a described in claim 5 wherein the cells in said connector portions have identical cross-sectional configurations, and said cell inserts also have identical cross sectional configurations. 
     
     
       7. A system as described in claim 6 wherein each conduit section has a connector portion at both ends of the section. 
     
     
       8. A system as described in claim 6 wherein the connector portions of the conduit sections are equal in length. 
     
     
       9. A system as described in claim 8 wherein each conduit section has a connector portion at both ends of the section. 
     
     
       10. A system as described in claim 6 wherein the length of each cell insert is substantially equal to the combined length of the two connector portions to be joined. 
     
     
       11. A system as described in claim 8 wherein each cell insert has a ridge protruding from its exterior surface around at least a part of its perimeter at a midpoint along the axial direction, and the length of the portions of said cell inserts on either side of said ridge is substantially equal to or slightly less than the length of a connector portion. 
     
     
       12. A system as described in claim 1 wherein each conduit section has a connector portion at both ends of the section. 
     
     
       13. A joint for connecting abutting sections of multi-cell conduit, said cells having inner walls formed by an integral web, comprising: a connector portion disposed at each end of each section of conduit to be joined, said connector portions having identical cross-sectional configurations, said connector portions having larger interior and exterior cross-sectional areas than corresponding interior and exterior cross-sectional areas of a main portion of said conduit, and wherein each cell of one section will have an associated cell in the other section defining pairs of associated cells;   a plurality of hollow cell inserts, the number of inserts for each joint corresponding to the number of cells in a section of conduit, said inserts having a length substantially equal to the combined length of the two connector portions to be joined, each of said pairs of associated cells having an associated cell insert having an exterior cross-sectional configuration corresponding substantially in geometry to an interior cross-sectional configuration of the connector portions of the pair of associated cells, wherein each of said cell inserts is inserted for substantially half of its length into one or the other of its associated cells leaving a protruding portion, and the joint is formed when the ends of the conduit sections are aligned and moved into abutment with each other, the protruding portion of each of said inserts being inserted into the associated cell of the other conduit section.   
     
     
       14. A joint as described in claim 13 wherein the multi-cell conduit comprises sections having four cells. 
     
     
       15. A joint as described in claim 14 wherein the exterior of the conduit is substantially square in cross-section. 
     
     
       16. A joint as described in claim 15, wherein the configuration of the cross-section of the connector portion contains four cells which are identical in cross-section, and the hollow cell inserts are identical and interchangeable. 
     
     
       17. A multi-cell conduit system having at least two sections of conduit to be joined end-to-end, said system comprising: a first and a second section of multi-cell conduit made of a polymeric material, each having an integral web forming four cells in an interior part of each section, each cell of said first section having an associated cell in said second section defining pairs of associated cells, each of said sections having a main portion and at least one integral connector portion, said connector portions having substantially identical cross-sectional configurations, said cross-sectional configuration being in the shape of a square with four rounded corners, each of said connnector portions comprising an expanded end portion wherein an interior and an exterior cross-sectional area is greater than an interior and exterior cross-sectional area of said main portions, each of said connector portions extending axially inwardly for a predetermined distance from an end of said conduit section;   each of said pairs of associated cells of said first and second conduit sections having a substantially identical cross-sectional configurations, and each of said pairs of associated cells having an associated thin walled cell insert, said cell inserts being identical in configuration and further being interchangeable, each of said cell inserts having an external cross-sectional configuration conforming substantially in geometry to an internal cross-sectional configuration of the connector portions of its pair of associated cells, each of said cell inserts further having a ridge protruding from its exterior peripheral surface at an axial midpoint thereof, said ridge protruding from at least the portions of the peripheral surface of said cell inserts which will be disposed facing outwardingly; and   wherein said cell inserts are adapted to extend into the connector portions of associated cells and are adapted to join each pair of associated cells of the first and the second conduit section when the sections are aligned along their longitudinal axis, and wherein the ridges of said cell inserts are adapted to form a substantially contiguous surface with the exterior walls of said connector portions when the conduit sections are joined.